Back-in parking or parallel parking generally require a relatively high maneuvering skill of a steering wheel. Especially, many beginning drivers are not good at the back-in parking or the parallel parking. In light of foregoing, recent suggestions have lead to a parking assist device capable of assisting the vehicle maneuvering upon the vehicle parking. For example, as a type of the parking assist device, a parking guiding device is described in JP11(1999)-208420A2. In this parking guiding device, a target parking position range, which is computed by a microcomputer mounted on a vehicle, is displayed and superimposed on an image of a target parking rage, which is taken by a camera mounted on a vehicle side body.
However, according to the above-described parking guiding device, which sets the target parking position with the image captured by the camera, there is a relatively long interval between the an the target parking position and a vehicle current position when the vehicle is about to back up. In this case, the target parking position may be displayed at a relatively small scale such that it may be difficult for a driver to set the target parking position with high precision. Therefore, there has been a possibility that the drive may be guided to an unwilling space when the vehicle is moved for parking and is approaching the target parking position. Under this condition, a relative relationship between the initially set target parking position and the current vehicle position after the rearward movement has not been updated. Therefore, even when the driver attempts to set the target parking position again, it may take time for the drive to modify the target parking position to be displayed.
The above mentioned matter that it may take time for the driver to modify the target parking position to be displayed may occur when the vehicle backs up in error during the target parking position modification.
A need exists for providing a vehicle backward movement assist device capable of updating and displaying a target parking position in response to a vehicle post-position when the vehicle moves.